What are the branches of the internal iliac artery?

Branches of the Internal Iliac Artery

The internal iliac artery divides into anterior and posterior divisions, with the anterior division giving rise to superior vesical, obturator, middle rectal, inferior vesical (or vaginal in females), uterine (in females), inferior gluteal, and internal pudendal arteries, while the posterior division gives rise to iliolumbar, lateral sacral, and superior gluteal arteries. 1

Anatomical Organization

Origin and Main Division

• The internal iliac artery arises from the common iliac artery at the level of the sacroiliac joint 1
• It descends as a trunk and then divides into anterior and posterior divisions 2
• Average length of the internal iliac artery is approximately 27.0 mm (range 0-52 mm) 3

Anterior Division Branches

The anterior division supplies the pelvic visceral organs and includes:

• Superior vesical artery
• Obturator artery
• Middle rectal artery
• Inferior vesical artery (in males)
• Vaginal artery (in females, replacing the inferior vesical artery)
• Uterine artery (in females)
• Inferior gluteal artery
• Internal pudendal artery 1, 4

The most prevalent branch of the anterior division is the internal pudendal artery, present in 90.5% of cases 4. The most common first branch is the umbilical artery (48.5%), while the most common terminal branch is the inferior gluteal artery (68.4%) 4.

Posterior Division Branches

The posterior division supplies the pelvic parietal structures and includes:

• Iliolumbar artery
• Lateral sacral artery
• Superior gluteal artery 1, 3

In 62.3% of cases, the posterior division branches arise from a common trunk. In the remaining cases, branches arise independently from the internal iliac artery, with the iliolumbar being the first branch in 28.3%, lateral sacral in 5.7%, and superior gluteal in 3.8% 3.

Anatomical Variations

The branching pattern of the internal iliac artery shows significant variations. According to modified Adachi's classification, the most common pattern (Type I-Group 1) occurs in 46.8% of cases 5. However, when focusing on the three major branches (superior gluteal, inferior gluteal, and internal pudendal arteries), approximately 80% follow a basic pattern where the internal iliac artery divides into:

1. The superior gluteal artery
2. A common trunk that further divides into the inferior gluteal and internal pudendal arteries 5

Clinical Significance

Surgical Considerations

• Knowledge of internal iliac artery anatomy is crucial during pelvic surgeries to prevent accidental hemorrhage and neurovascular injuries 1
• For ligation of the internal iliac artery in cases of acute hemorrhage, ligation 5 cm distal from the common iliac bifurcation would typically spare posterior division branches 3
• The internal iliac vein is typically lateral to the artery (70.6% on the left side and 93.3% on the right side) 3

Interventional Procedures

• Detailed knowledge of the branching pattern is essential for interventional radiologists during:
  • Arterial embolization for hemorrhage control
  • Management of pelvic fractures
  • Selective catheterization for intra-arterial chemotherapy
  • Embolization of pelvic tumors 1

Endovascular Considerations

• When treating iliac aneurysms, the American College of Cardiology recommends preservation of at least one hypogastric artery (internal iliac artery) to decrease the risk of pelvic ischemia (Class 1, Level B-NR recommendation) 6
• Complications of hypogastric artery exclusion include buttock claudication (27% with unilateral exclusion, 36% with bilateral exclusion), erectile dysfunction (10% in men), and rare but serious conditions such as bowel ischemia and spinal ischemia (<1%) 6

Anatomical Access

• The retroperitoneal area containing the internal iliac artery can be accessed after cutting the pelvic peritoneum 2
• For localization of branches during procedures, the median diameter of the anterior division at its origin is approximately 5.76 mm with a median cross-sectional area of 24.77 mm² 4

Understanding these anatomical details is essential for surgeons, interventional radiologists, and other specialists working in the pelvic region to minimize complications and optimize procedural outcomes.